John fell asleep _______ he was listening to the CD. [ ]
A.after
B.while
C.before
D.if
答案:B
TOF肌松监测的T4/T1值是多少时即可满足手术的要求()
A.小于50%
B.小于35%
C.小于25%
D.小于15%
E.小于10%
教学手段的灵活性原则